Isolation switches

[switch10]

The isolation switch question .

Recently changed a fusebaord for a customer just because they wanted rcbos and done some other minor works , now customer is asking me to remove and blank off 3 extractor fan isolation switches that were allready installed (house is going to be a hmo ) , extractor fans are humistat fans ,

Would you be happy to remove them and blank off? Personally I think as they’re there then they should stay , rather than join cables and blank off . House is 3 story , bathroom 1 is on ground floor , fuse board also on ground floor so easy to isolate without isolation switch .

But if a fault on 1st or Second floor then bit harder in the dark .

Plus vent axia state there should be a 3 pole isolation switch so I’m kind of sticking with leaving them based on that.

What’s your thoughts?

The jobs hour and 20 away just to remove these seems a wasted trip to be honest

 

[Andy™]

go blank them. nothing in 7671 says you can't.

also don't understan the mentality of 'i need an isolator or ill have to switch off lights and work in the dark'. you'd be ****** if you neede to work on the actual lights then

by leaving them in, you can guarantee they will be turned off and the house will then be full of damp... not your problem but i can understand why many landlords do want them on

wasted trip? maybe, but if you're getting paid then who cares

 

[binky]

go blank them. nothing in 7671 says you can't.

also don't understan the mentality of 'i need an isolator or ill have to switch off lights and work in the dark'. you'd be ****** if you neede to work on the actual lights then

by leaving them in, you can guarantee they will be turned off and the house will then be full of damp... not your problem but i can understand why many landlords do want them on

wasted trip? maybe, but if you're getting paid then who cares

I thought there was a requirement to have isolation for servicing of fixed equipment. Same as fitting shower isolators or fused spurs for boilers and immersions. However, I totally get your point about tennants who seem to like switching fans off. Perhaps a box over the isolator to hide it would be a suitable compromise.

 

[ProDave]

I have asked many times for someone to show me the reg that says we must have a fan isolator switch and nobody has. I think someone once miss interpreted a reg saying big industrial size fans must have a local isolator so when someone is working on a 3HP motor in a plant room changing a belt it cannot start unexpected. And then applied that to a poxy little domestic extract fan.

So until someone shows me where it says you must have one on a domestic extract fan then I am happy to not fit them or remove them.

I learned long ago that tenants are their own worst enemy, when called to investigate damp in a bathroom only to find the fan isolator switch turned off and the fan had never been working. That was the moment I decided rental property = no fan isolator switch.

 

[Murdoch]

IIRC isn’t this reg in the building regulations.

I would connect the cables using the same connectors on the switch then the tenants can’t switch it off

 

[switch10]

go blank them. nothing in 7671 says you can't.

also don't understan the mentality of 'i need an isolator or ill have to switch off lights and work in the dark'. you'd be ****** if you neede to work on the actual lights then

by leaving them in, you can guarantee they will be turned off and the house will then be full of damp... not your problem but i can understand why many landlords do want them on

wasted trip? maybe, but if you're getting paid then who cares

I understand nothing in bs7671 says must have , but as these are new vent axia fans and the customer doesn’t understand that due to manufacturers instructions saying they must be fitted to a 3 pole isolation switch , that if they are removed then the warranty will be void if in the event of a faulty unit .

And to be fair the units fitted are that quiet I don’t think they will be getting turned off

 

[binky]

I understand nothing in bs7671 says must have , but as these are new vent axia fans and the customer doesn’t understand that due to manufacturers instructions saying they must be fitted to a 3 pole isolation switch , that if they are removed then the warranty will be void if in the event of a faulty unit .

And to be fair the units fitted are that quiet I don’t think they will be getting turned off

move isolators out of reach?

 

[Phoenix]

If you wanted to leave some form of switching off for mechanical maintenance then you could replace them with a double pole secret key grid switch, opening live and switch wire, with neutral jointed through in the back?

 

[kerching]

If you wanted to leave some form of switching off for mechanical maintenance then you could replace them with a double pole secret key grid switch, opening live and switch wire, with neutral jointed through in the back?

I use a lot of Click Minigrid stuff ( other systems are available) with a bit of ingenuity/lateral thinking it is quite simple to wire a double pole switch module and a DP key switch module onto a single plate and provide true L / S-L / N isolation for the fan and still have the light switch working the fan. I've done it this way for decades

Just saying

 

[Fleeting]

I use a lot of Click Minigrid stuff ( other systems are available) with a bit of ingenuity/lateral thinking it is quite simple to wire a double pole switch module and a DP key switch module onto a single plate and provide true L / S-L / N isolation for the fan and still have the light switch working the fan. I've done it this way for decades

Just saying

If those switches only comply with 60669-1 then they are not considered suitable for use as isolators.

 

[binky]

I use a lot of Click Minigrid stuff ( other systems are available) with a bit of ingenuity/lateral thinking it is quite simple to wire a double pole switch module and a DP key switch module onto a single plate and provide true L / S-L / N isolation for the fan and still have the light switch working the fan. I've done it this way for decades

Just saying

ingenious, took some head scratching and sketching out on a bit of paper to work that out

 

[binky]

If those switches only comply with 60669-1 then they are not considered suitable for use as isolators.

they are, I've just had a look.

 

[Fleeting]

they are, I've just had a look.

According to the spec they comply to 60669-1 and according this they don't unless they have additional standards to them.

 

[binky]

cross purposes, they do comply with 60669-1, but I've just had a look at several cheap fan islotors on line and they are also 60669-1, bar MK which seem to be 60947-3. So just about every fan isolator I've fitted for years would appear to be non-compliant as an isolator. Interesting, as I'm sure suppliers would not work to the wrong standard????

 

[Fleeting]

cross purposes, they do comply with 60669-1, but I've just had a look at several cheap fan islotors on line and they are also 60669-1, bar MK which seem to be 60947-3. So just about every fan isolator I've fitted for years would appear to be non-compliant as an isolator. Interesting, as I'm sure suppliers would not work to the wrong standard????

I always check fan isolators to ensure they are what they say.

 

[kerching]

NICEIC AE said it HAD to be triple pole
I disagreed
Kerch. 1. NIC. 0

 

[Murdoch]

Did the NIC say you had to have one?

 

[Phoenix]

ingenious, took some head scratching and sketching out on a bit of paper to work that out

I'm still not sure what hes getting at, but its late on a friday, so I'm not going to beat myself up about it, give us a clue?
Does it involve the cirucit being three plated at the isolation swithc rather than anywhere else?

As to the not suitable forn isolation, I think its because the standard dones't require the devices to have 3mm contact separation, I know the MK ones do go beyond the requires and do and are likely suitable, no idea on the click ones. But the fan switch is "switching off for mechanical maitenance" isnt it, not isolation, so probably no need to break the neutral as long as all lines are disconnected so it cant move (not that a bathroom fan is going to take your fingers off anyhow...)

Not sure if it was prevelent anywhere else, but round here, I keep finding timer fan instaled in the 1990s, where there is a fused spur breaking L and N to the fan, but switch wire in connector block in the back off the box, so you turn it off, and fan stops, but the SL to the electronics is still live and now backfeeding the open neutral. I guess they didn't have 3pole isolators back then, but why not use a 20A DP switch and break L and SL.

 

[kerching]

Did the NIC say you had to have one?

He said it had to isolate all current carrying conductors
I,said It did
He said It didn't as it was only two pole
I said it did and showed him a sketch
He said "Oh!"
I said "apology accepted" and show me the reg that says it needs one anyway

He said there wasn't a specific reg ( so no reg, I,don't do non specifics ) but some MIs required it

 

[Fleeting]

TT system would require isolation of the neutral conductor.